Active matrix substrate, method for manufacturing same, and liquid crystal display apparatus

A method for manufacturing an active matrix substrate on which a thin-film transistor serving as a switching element is formed, the method comprising the steps of:

• (a) forming a pattern of a line on a substrate;
• (b) forming an insulating layer so as to cover the line;
• and
• (c) patterning the insulating layer,
• wherein:
• in the step (c), the insulating layer on an upper surface of the line is removed so that the upper surface is exposed in a region where the line is electrically connected with a component, whereas the insulating layer which has contact with an edge face of the line is left in the region, wherein the line has a multilayered structure comprising (i) a line in a top layer, (ii) a middle line directly below the line in the top layer, the line in the top layer protruding, in a direction in which the line in the top layer extends, more than the line directly below the line in the top layer as viewed in a cross sectional direction, and (iii) a bottom line located directly below the middle line, the bottom line protruding, in the direction in which the line in the top layer extends, more than the line in the top layer as viewed in the cross sectional direction
• wherein the insulating layer is provided on the substrate with a thickness of not more than a film thickness of the at least one line so as to have contact with at least an edge face of the line directly below the line in the top layer, the edge face being on an extension of a longitudinal direction of the line directly below the line in the top layer.